German Patent Disclosure Document DE-OS No. 30 00 520 teaches such a method for the production of a helical spring reinforced with carbon fibers. There a strand comprising carbon fibers and plastic resin is coiled into a spiral groove of a cylindrical core and is then solidified. The solid spring can then be removed from the core.
In the known method the outer region of the strand not surrounded by the spiral groove is wound with an easily removable and tension proof tape. This winding is relatively expensive and does not assure an accurate cross-section shape of the strand. In addition cross-sections narrowing to the outside such as for example a round cross-section particularly desirable for helical springs cannot be produced.